Bagrat Amirikian, PhD
Assistant Professor, Department of Neuroscience
Computations in the Motor Cortex: Cortical Microcircuits, Functional Columns, and Motor Control Signals
Cortical processing is mediated through the short-range (local microcircuits) and the long-range (interaction involving distinct microcircuits) connections between excitatory and inhibitory neurons distributed across distinct cortical layers. My current research interests are focused on two problems. i. Whether do these spatially structured intrinsic connections induce functional modularization of the motor cortex (e.g., segregation of neurons with coherent properties into columns), and how do they shape the computation of neural motor control signals? ii. How does one translate neural signals extracted from the motor cortex into signals appropriate for "intelligent" motor control of prosthetic devices (e.g., multijoint robotic arm)? To investigate these problems we use the methods of neural network modeling, and carry out very large-scale simulations on high-performance massively parallel supercomputers.
Zick, JL, Blackman, RK, Crowe, DA, Amirikian, B, DeNicola, AL, Netoff, TI & Chafee, MV 2018, ‘Blocking NMDAR Disrupts Spike Timing and Decouples Monkey Prefrontal Circuits: Implications for Activity-Dependent Disconnection in Schizophrenia’ Neuron, vol. 98, no. 6, pp. 1243-1255.e5. https://doi.org/10.1016/j.neuron.2018.05.010
Christopoulos, VN, Boeff, DV, Evans, CD, Crowe, DA, Amirikian, B, Georgopoulos, A & Georgopoulos, AP 2012, ‘A network analysis of developing brain cultures’ J Neural Eng, vol. 9, no. 4, p. 046008. https://doi.org/10.1088/1741-2560/9/4/046008
Naselaris, T, Merchant, H, Amirikian, B & Georgopoulos, AP 2006, ‘Large-scale organization of preferred directions in the motor cortex. I Motor cortical hyperacuity for forward reaching’ J Neurophysiol, vol. 96, no. 6, pp. 3231-6. https://doi.org/10.1152/jn.00487.2006
Naselaris, T, Merchant, H, Amirikian, B & Georgopoulos, AP 2006, ‘Large-scale organization of preferred directions in the motor cortex. II. Analysis of local distributions’ J Neurophysiol, vol. 96, no. 6, pp. 3237-47. https://doi.org/10.1152/jn.00488.2006
Amirikian, B 2005, ‘A phenomenological theory of spatially structured local synaptic connectivity’ PLoS Comput Biol, vol. 1, no. 1, p. e11. https://doi.org/10.1371/journal.pcbi.0010011
Georgopoulos, AP, Whang, K, Georgopoulos, MA, Tagaris, GA, Amirikian, B, Richter, W, Kim, SG & U?urbil, K 2001, ‘Functional magnetic resonance imaging of visual object construction and shape discrimination: relations among task, hemispheric lateralization, and gender’ J Cogn Neurosci, vol. 13, no. 1, pp. 72-89.
Amirikian, B & Georgopoulos, AP 2000, ‘Directional tuning profiles of motor cortical cells’ Neurosci Res, vol. 36, no. 1, pp. 73-9.